Conventional methods of achieving well dispersed blends of inorganic material or cellulose fiber in a polymer matrix include simple mixing, high shear mixing (as developed in a Kady mill or Cowles mixer, or a high pressure homogenizer) or through the use of dispersants. With such methods, it can be difficult to disperse inorganic particles or fibrous materials uniformly throughout the polymer matrix. For example, the high water content and hydrophilic nature of nanocellulose makes it difficult to disperse this material in many polymeric systems, such as plastics and other hydrophobic composites. Additionally, it can be difficult with existing methods to produce a high solids dispersion of some materials. For example, it is difficult with existing methods to achieve greater than 3% solids content of nanocellulose in a water-based slurry and still have a slurry that flows or can be pumped. Similarly, it is difficult with existing methods to achieve greater than 70-72% solids content of inorganic materials in an aqueous slurry that is still pumpable.